In thin film transistor (TFT-LCD) display technologies, the predominant methods for achieving initial alignment of liquid crystal molecules include rubbing a polyimide (PI) film layer so as to form an alignment layer on an array substrate and a color filter substrate. In a rubbing process, a rubbing roller is an important component for rubbing a polyimide film layer. A rubbing roller usually comprises a roller mandrel, a rubbing fabric and an adhesive tape, and the rubbing fabric is wrapped around the outer surface of the roller mandrel via the adhesive tape. With the roller mandrel being rolled, it is possible to achieve a rubbing treatment against a polyimide film layer, thus the rubbed polyimide film layer can achieve the initial alignment of crystal molecule molecules in operation in a TFT-LCD.